data regarding epidemiology are limited and they are less common
than the intracranial tumors (about 1:10). In most series, the
average age at diagnosis is 40 years, ranging between 11 days &
74 years. Both sexes are equally involved. More than 70% of the
tumors were located in the thoracic part or cervical (in that
order) of the spinal cord.
is convenient to classify the spinal cord tumors by their location
within the spinal cord,
extramedullary intradural, intramedullary, and extradural.
the extradural tumors do not come under spinal cord tumors, it is
discussed here briefly.
Extramedullary intradural tumors are the commonest spinal
cord tumor (84% of all intradural tumors). Neurofibromas(29%) and
meningiomas(25%) are the common ones.
are more common in middle aged women and in the thoracic region.
Exophytic ependymomas and astrocytomas account for about 20%.
Sarcomas, vascular tumors, epidermoids, lipomas etc are occasionally
Intramedullary tumors are the commonest spinal cord tumors
in children. Gliomas (mainly ependymomas & astrocytomass) make
up almost 70% of all intramedullary tumors. In children astrocytomas
are most frequently encountered, in some material representing up to
81% of such tumors, while in adults alone ependymomas may account
for up to 56% of all intramedullary tumors. Vascular tumors,
represented by hemaingioblastomas and cavernomas, add upto almost
15% of all intramedullary tumors. Among the other tumors are found
cases of subependymomas, sarcoidosis, neurofibromas, ganglioglioma,
gangliocytoma, oligodendroma and astrogliosis. In the literature
there have also been case reports on primary malignant lymphomas and
neurocytomas in the spinal cord.
malignant tumors from the brain, such as medulloblastoms, may
Extradural tumors are mostly metastatic. They spread
into spinal cord from contiguous structures. About 5% of all
patients with cancer develop vertebral metastasis. Lately,
primary non osseous lymphomas are being reported
tumors can be divided into two groups: primary, i.e.
arising within the bone, and secondary, i.e. metastatic
to bone. Within the group of primary bone tumors are
both benign and malignant forms.
tumors are predominantly aneurismal bone cysts and
osteoblstomas, whereas malignant forms include Ewing’s
sarcoma, chordomas, chondrosarcomas, and mesenchymal
tumors can cause symptoms due to compression of the cord and
interrupting the cord's blood supply. Initially, the veins get
compressed, resulting in congestion and edema. Arterial compression
occurs later, which may sometimes lead to distant effects; pressure
at the D4 and D5 levels may cause a greater deficit because of the
watershed area in the vascular supply of the cord at this level.
pressure on the cord and roots leads to disturbed cord function, the
long tracts being affected early. Lumbar puncture may sometimes
cause a shift in the position of the tumor leading to a sudden
increase in the neurological deficit.. In long standing tumors,
there may be gliosis, and the recovery following surgery may not be
meningiomas and other tumors do not, in general, differ from their
from their intracranial counterparts.
gliomas, although share several characteristics with intracranial
gliomas, there are some interesting differences.
spinal cord are rare neoplasms, about 10 times less common than
astrocytomas of the brain. The average age at diagnosis is between
35 and 40 years. Astrocytomas of the spinal cord do not show the
correlation between increasing grade and increasing age at diagnosis
that is so prominent with cerebral diffuse astrocytomas.
cord astrocytomas are graded according to the same WHO criteria,
used for cerebral astrocytomas, and grade is a strong prognostic
indicator. Low-grade astrocytomas (WHO grade II/IV) comprise about
75 - 90% of tumors, with the remainder being high-grade astrocytomas
(WHO grades III/IV and IV/IV). Tumors typically involve a focal
segment of the cord, and have a fairly even incidence along its
length, but rarely may involve a large portion of the cord in a
condition called "holocord" astrocytoma. The tumor may
grow in a diffuse manner with indistinct margins between tumor and
the adjacent normal spinal cord tissue, and can extend along spinal
nerve roots. Pilocytic astrocytomas have discreet margins.
important feature is the presence of a tumor associated syrinx,
which occurs in about 40% of patients with astrocytomas of the
spinal cord. Syringes are more common with low-grade than high-grade
astrocytomas, are more frequent the further rostral the tumor lies
along the cord, and they appear to favor the rostral aspect of cord
above the tumor. Syrinx may be less common with astrocytomas than
with ependymomas. With respect to syrinx formation, normal CSF flow
in the central canal of the cord is disrupted by the presence of the
mass lesion. This mechanical explanation probably accounts for the
fact that tumor-associated syringes are typically rostral to the
of the spinal cord are slightly more common than spinal cord
astrocytomas. The average age of patients is between 35 and 45
years, an age which is higher than for intracranial ependymomas.
ependymomas are thought to arise from ependymal cells lining the
central canal. Cellular ependymomas are distributed evenly along the
length of the spinal cord, whereas myxopapillary ependymomas occur
almost exclusively at the filum terminale and occasionally the conus
medullaris. Tumors may extend over several spinal segments, and may
have a substantial exophytic component. Holocord lesions are rare.
Syringes or tumor-related cysts may be more common with ependymomas
than with astrocytomas of the spinal cord. The lesions are usually
classification includes myxopapillary ependymoma (WHO grade I/IV),
ependymoma (WHO grade II/IV) and anaplastic ependymoma (WHO grade
III/IV). The two low-grade lesions are more common than anaplastic
ependymoma. Anaplastic ependymomas may be associated with
leptomeningeal spread, although this complication occurs with the
lower grade lesions as well. Ependymomas, including those arising
from the spinal cord, have the unusual propensity to spread outside
of the neuraxis. This is particularly true for subcutaneous
myxopapillary tumors that arise over the sacrococcygeal region.
Metastasis to lung, skin and kidney have been documented.
ependymomas of the spinal cord are usually slowly growing lesions
with little tendency to undergo anaplastic progression to higher
grades of histology or more aggressive biological behavior.
cord tumors produce symptoms due to compression of nerve root or
cord, and ischemia vascular compression.
of the cord by the dentate ligaments and filum terminale may result
when expanding lesions oppose this resistance.
main symptoms are, pain, weakness, sensory disturbance, and
autonomic disturbances. In addition, there may be a vertebral
deformity, especially in children.
tumors mimic the commoner extramedullary tumors; the root pain is
well defined. The pain is aggravated by coughing and sneezing and
other spinal movements. Autonomic disturbance is rare, unless it is
a rapidly progressive lesion, such as, metastasis.
tumors grow in relation to a nerve root. Chronic progressive
radicular pain, especially at night, may precede all other symptoms.
The combination of pain associated with myelopathy can
progress for a long time by the patients' ability to cope. Autonomic
symptoms are delayed as the center of the cord is involved late
unlike the intramedullary tumors. Radicular pain may simulate an
angina at times.
tumors infrequently progress slowly, & for a long time often
with rather mild symptoms and ill-defined pain. The mean
distribution of symptoms prior to operation are more than 4-5 years,
ranging between 3 months & 11 years. Since these tumors often
destroy structures near the centre of the spinal cord, the crossing
pain and temperature fibers are frequently damaged and there is
early involvement of bladder fibres. In the classical case the tumor
therefore presents with an early segmental differential sensory
deficit, later followed by long tract signs, with subsequent
weakness & wasting of musculature in the extremities. However,
the presenting symptoms do not necessarily suggest an intramedullary
process. Different degrees of paraesthesias, sensory loss, motor
deficits and atrophy of the extremity musculature atrophy are then
children muscular weakness with gait disturbances,
back or extremity pain and urinary dysfunction are the most common
presenting symptoms. Up to 30% of the pediatric patients present as
spinal deformities. Spinal
deformities, such as kyphosis or scoliosis, when associated with
pain often can be warning signs of a spinal cord tumor.
lesions are often signaled by mid-lying cutaneous markers such as
hemangiomas, a dural sinus tract, etc. Meningiomas,
schwannomas, and neurofibromas can be suggested by other
and symptoms with relation to site:
may be mild
AJ, decreased KJ
may be rapid
may be slow.
isolated conus tumor is not seen in practice, and at presentation,
it usually compresses the roots of cauda equina, and presents as
mixed or a cauda equina type of syndrome.
today's advanced imaging, it is vital to ascertain the site of the
lesion before requesting an investigation.
must be remembered that the spinal cord is much shorter than the
vertebral column and ends at the lower border of the L1 vertebral
body. Hence, the spinal cord segments are not situated opposite the
is a progressive increase in the difference between the cord
segments and vertebral bodies from above downwards.
8 cervical segments extend from the foramen magnum to the upper C7
12 dorsal cord segments lie opposite the D1 to the lower body of D9.
D4, D8, and the D12 cord segments lie opposite the D3, D6, and D9
vertebral bodies, respectively.
lumbar cord segments are opposite the D10, D11, and D12 vertebral
sacral and coccygeal segments therefore, lie opposite the L1 body.
may alert a clinician. A widened spinal canal (intramedullary
tumor), bony changes (extradural and extramedullary-intradural), and
widened intervertebral foramen (neurofibroma) warrant a further
imaging. Paravertebral shadows may suggest a malignancy.
classical diagnostic tool was myelography.
an intramedullary tumor almost invariably showing up as a widening
of the cord shadow.
filling defect displacing the cord to one side is characteristic of
or brushlike transverse filling defect suggests an extradural
resonance imaging (MRI) is the most useful radiological study for
evaluating the spinal canal and its contents and
is the imaging of choice. It
is useful both in defining the extent of disease and the possible
pathology involved and in evaluating the spinal cord and its
surrounding structures in multiple projections.
myelography is useful, when MRI is not possible.
The computed tomography (CT) scan is useful in particular for
defining bony abnormalities. CT scanning tends to offer very
little insight into intramedullary disease by itself. Its
delineation of soft tissue changes is vastly inferior to that noted
by the MRI scan. Occasionally, CT is combined with myelography,
but usually this does not give as clear an evaluation as that given
excision is the treatment for extramedullary tumors.
Total excision along with involved dura in case of meningiomas is
possible and recommended. Sacrificing the nerve root during total
excision of neuromas may be justified.
traditional treatment of intramedullary gliomas has
been biopsy followed by radiation therapy. However more & more
neurosurgeons have changed to aggressive treatment of these
neoplasms. The major reasons for this are the diagnostic and
operative technical developments that have taken place for the last
few years. Thus, MRI increases the accuracy of the diagnosis, and
together with perioperative ultrasonography it allows an exposure
that minimizes bone removal while maximizing tumor accessibility.
the operative microscope and bipolar coagulation marked the dawn
of modern treatment of these lesions, & the introduction of
ultrasonic aspiration and surgical laser dramatically modified the
strategy in favor of aggressive surgical treatment.
experienced hands radical resection of ependymomas is now possible,
with good functional results. The same is true for
haemangioblastomas and cavernomas. Because of their clear
demarcation ependymomas and vascular tumors often can & should
be totally resected, without risk of increased morbidity.
regards to malignant astrocytomas most surgeons agree that surgery
has only little impact on the clinical course. A less radical
intervention, to secure minimal surgical morbidity is therefore
surgical treatment of low grade astrocytomas is a bit more
controversial, with some authors advocating radical removal of the
tumor while others claim that total removal does not yield better
outcome compared to less aggressive resection.
syrinx must be drained.
operative deformity, subluxation and instability is reportedly
common following extensive laminectomy in the young (under 18yrs of
age), especially in the cervical region. Reportedly, laminoplasty
can prevent a deformity.
advise stabilization procedure as preventive measure. Most surgeons
advise a close follow up.
therapy for intramedullary tumors has been controversial
during the last decade. Clearly, radiation is accompanied by a risk
of spinal injury the functional tolerance of the cord being 10 –
15% lower than that of the brain. Radiation sensitivity increases
with the length of the cord irradiated, the size of the daily dose,
and the total dose given. A total dose of 5000 rads given in 25
fractions over 5 weeks is usually considered acceptable.
all studies support no indication for post operative irradiation for
intramedullary ependymomas and low grade astrocytomas.
regards to high grade gliomas,
for clinically progressive lesions, and for tumors in which a
substantial resection cannot be achieved,
most surgeons still agree that radiation therapy is to be
recommended, although with uncertain results.
Craniospinal irradiation is recommended for high grade ependymomas
due to the higher risk of tumor growth in the CSF pathways.
is clearly of value in metastatic lesions.
can be considered in patients with progression of disease after
radiation therapy. There are a number of case reports and small
series indicating chemotherapy responses in pediatric and adult
spinal cord astrocytomas. Although astrocytomas of the cerebral
hemispheres are not highly responsive to chemotherapy, recent
evidence has suggested that astrocytomas with 1p loss may also be
sensitive to chemotherapy.
can also be administered in ependymomas with progression of disease
after radiation therapy, since ependymomas demonstrate some
responsiveness to chemotherapy.
prognosis for extramedullary intradural tumors is good following a
reported results of treatment of intramedullary tumors are still
difficult to interpret and evaluate because of heterogenous
management strategies, small number of patients and short periods of
follow up. Clearly, most patients experience some neurological
morbidity in the immediate post operative period, deficits which in
benign lesions may improve within 3-6 months.
suggest that the surgical outcome at follow up is directly related
to the patients’ pre operative status. Thus recovery from a
significant & long standing deficit rarely occurs.
factors for patients with spinal cord gliomas include histological
grade and duration of symptoms prior to diagnosis.
is almost always due to tumor growth at the original tumor site,
although the possibility of simultaneous tumor dissemination
throughout the neuraxis should be also considered, especially with
present malignant astrocytomas of the spinal cord are
incurable lesions with a behavior that is very similar to that of
the histologically identical lesions found in the brain. Thus
although operation may result in palliation, malignant astrocytomas
usually recur within a year, with a fatal outcome in less than 2
years after operation. The
overall 5-year survival for patients 30% with high-grade tumors.
prognosis of low grade astrocytomas is of course better, with
some claims of an excellent long term prognosis. Most surgeons are
more guarded. The
overall 5-year survival is 70-90%.
outcome following surgery of intramedullary ependymomas is
more gratifying. Radical removal can usually be achieved, and if so
tumor recurrence is very unusual. Overall
survival of series of patients with low-grade ependymomas of spinal
cord are in the range of 85% 5-year survival. Survival rates are
even higher in patients with myxopapillary ependymomas and are
significantly lower in patients with anaplastic ependymomas.